A prior art method (Rits V. A., Shchupliak A. A., Gladkov O. A., Sokolova I. V., Pelevin L. A. “Method for wastewater neutralization”, Patent RU No. 2108811, published on 20 Apr., 1998) for wastewater neutralization provides production of humates by mixing wastewater with an alkaline agent, activation of reaction mixture by hydrodynamic cavitation effect at a temperature of 50–170° C. with simultaneous feed of compressed air under a pressure of 0.2–1.6 MPa. The activated mixture is further heated to an operating temperature of 140–190° C., charged into a reactor, with concurrent supply of compressed air kept at the temperature, settled, and the sediment is separated.
A method for production of humic concentrate from natural humites and caustobioliths of carbon series according to the invention comprises high-temperature treatment of source raw material, mixing with an alkaline agent, oxidation and cooling. Humic concentrate contains hydrated humic acids, humic acid salts and mineral components of source humites and caustobioliths bonded chemically with contained humic acids. (Patent RU 2125039, Shulgin A. I. et al., published 20 Jan. 1999).
The method for producing humic concentrate is realized by electrolysis of water solutions of humic acid salts previously extracted by an alkaline reagent from natural raw material; during electrolysis, the potential set at the anode is sufficient for discharge of humic acid anions but lower than the potential of discharge of hydroxyl ions, which provides production, on the anode surface, of the target humic concentrate continuously withdrawn from the zone of electrolysis.